Improvement in flour and middlings purifiers



To all 'whom it may concern:

UNTnn STATES APATENT OFFICE.

JOsEPHfYLAOROIX, OF FRIBAULT, MINNESOTA.

IMPR'VEMENTINMFLOUR AND MIDDLINGS PURIFIERS."v

. Specification forming part of Letters Patent No. 149,869., dated April 2l, 1874; application filed April 1o, 1874.-

Be it known that I, JOSEPH LACROIX, of Faribault, county of Rice, State of Minnesota, have invented a new and useful Improvement in Flour and Middlings Purifiers, of which the following is a specication:

Figure 1 is a'longitudinal vertical section of my improved machine.l Fig. 2 is a top or plan view of the vibrating conveyer.

The object of my invention is to purify the middlings without separating or grading them at the same time, or with the same machine; and to remove the ne and light impurities fromthe middlings, either before or after their passing overa separating or grading machine. The middlings passing over the last mentioned machines can only be partially purified, the greatest and best part of them going through at .the head of the machine without having the benet of the air-blast. It follows that, in order to obtain a perfect purication of the middlings, their whole body should be subjected to a continuous current .of air without separating them gradually. The object of my invention is also to separate and grade flour by separating the light and less pure iiour from the heavier and purer, the light ilour being drawn oif by the suction-fan and discharged into a proper receptacle, which may be rebolted and purified, if desired. My invention consists in a conveying-frame arranged in an air-tight chamber, and provided with alternate slats and transverse openings, larger than the particles of material passing over it, and through which a blast of airis forced upward in thin sheets to keep the iiour or middlin gs from falling through said openings, and raising and carrying off the light impurities; and also in connection therewith a suctionfan to assist in removing the impurities, as will be hereinafter more fully described.

A is an air-tight chamber, in which is sus pended, by links a, or otherwise, the convey ing-frame B, operated by a double eccentric, C, or similar means. The conveying-frame B is constructed of slats D, made of zinc, tin, wood, or other suitable material, leaving transverse openings d between them, from one-sixteenth to one thirty-second of an inch in width, through which currents of air from a blast-fan,

E, pass in thin sheets, and keep the middlings or flour passing over the conveying-frame from falling through said openings, and also raise up and separate the light impurities to be drawn ofi' by the suction-blast from fan F. E is a fan-blower placed in front of the machine, the blast of which is introduced into the chamber G below the conveying-frame. This air-chamber G may be constructed so as to vibrate with the conveying-frame, as clearly shown, or it may form a lower section of the main chamber with the vibrating conveyingframe supsended over it, and dividing it from said main chamber perfectly without allowing the air from the blast-fan to pass anywhereV but through the transverse openings in the conveying-frame. The air-chamber G, by preference, is made decreasing in height from the opening communicating with the mouth of the blast-fan to the other end of it, as shown in Fig. 1, in order that the air shall act equally on all parts of the conveying-frame. The slats D forming the upper surface of the conveyingframe, are beveled on their under sides or edges toward the top of the transverse openings, in order to let the air through more freely and more eectually, and also, in case any flour or middlings should fall through the openings into the air-chamber below when the machine is first started, that theymay be easily blown back through the same openings into' the main chamber as. soon as the machine is in full motion. I is a flexible tube o r band connecting the mouth of the blast-fan withthe air-chamber G, when said chamber is made to vibrate with and form part of the conveying frame.` This flexible tube is dispensed with when the chamber G is made stationary. F is the suction-fan, placed in the upper part of the machine to draw off the air containing the light impurities separated and raised up from the material passing over the conveying-frame by the currents or thin sheets of air from the blast-fan. b is aninelined hopper, from which the iiour or middlings to be operated upon are fed. b is an opening at lower end of the hopper b, regulated by a slide-valve, b2, through which the ilour or middlings pass in regulated quantity to an inclined board or plate, b3,- which acts as the feeder, and is supported and carried by the vibrating conveying-frame in such manner that the motion of the convey7e ing-frame causes the iiour or middlingsL supplied to the feeder to be discharged on the conveying-rame. The chamber A, at its lower part, extends over the whole surface of the conveyingvframe, but decreases gradually upward toward the point A', where it opens into a :narrow passage regulated by the slide c, which connects this chamber with the fanchamber F. The fau shafts and eccentric shaft are all driven by pulleys and belts from any convenient power.

By this construction of conveyingfframa the flour or middlings carried over it by its vibrating movement are intermittently subjected to thin sheets of air passing up through the transverse openings from the blast-fan, which keep the material from falling through, and cause the dustand all other impurities to rise into the upper part of the main chamber, where it is subjected to the suction from, and drawn ofi by, the exhaustfan F. The purified material passes over the end of' the conveying-frame into any proper receptacle, or to a separator to be graded, if desired.

Fig. 3 is a modification of the conveyingframe B, in which is shown a sieve covered with tin, wood, or other suitable material, leaving spaces between them for the currents of air to pass through, in a similar manner as the form of conveying-frame shown in Fig. 2.

I do not wish to contne myself to a vibrating conveying-frame, as an inclined stationary conveyingframe, constructed in the same manner, could be used, as the inclination vof the conveying-fra1ne, assisted by the blast of air, would cause the flour or middlings to travel toward the lower end thereof. Neither do I wish to confine myself to the use of both a blast and a suction fan. The air from a blastfau passing upward through the conveyingframe will keep the material from yfalling through, and will also carry ofi' the light irnpurities. I prefer, however, the use of the suction-blast in connection therewith to assist in removing the impurities.

I am aware that a blast and suction fan used in connection with a screen are old, and such I do not claim; but

What'I claim as my invention, and desire to secure by Letters Patent, is Y 1. In a flour or middlings purifier, the conveying-frame B constructed of alternate slats D, and transverseopenings d, in combination with the blast-fan E for forcing a blast of air in thin sheets upward through the transverse openings of the conveying-frame, to keep the material from falling through, and separate and carry oft' thev light impurities, substantially in the manner described. Y

2. The combination, with the vibrating conveying-frame B, provided with alternate slats D, and transverse openings d, of the blast-fan E and the suction-fan F, substantially as and for the purpose described.

3. The combination, with the vibrating conveying-frame B, and vibrating air-chamber Gr, of the blast and suction fans E and F, substantially as and for the purpose specified.

f JOSEPH LACROIX. y Witnesses:

THos.' JEWELL,

WM.VE. GHAFFEE. 

